120ED vs. 111EDT

I hate buying a scope without some reviews to compare. I'm considering the purchase of an Orion Eon 120ED or an Astro-Tech 111EDT. On one hand the Orion has an FPL-53 element though still a doublet and on the other hand the Astro-Tech is a triplet but of unknown glass type. I plan to use the scope for both visual work and imaging with my D-SLR. I know the larger aperture could show more color, but it has alonger f/ratio and supposedly better glass but the smaller aperture has a shorter f/ratio and a triplet lens which supposedly provides superior color correction especially for astro-photography.
Any and all comments are welcome.

Thanks,

Len J.

You'll get better quality control with a Vixen. If you're going to get a rerfractor but don't want to get into the real high end then you might look at Vixen.

I personally would prefer a well quality controlled Newt to a cheap refractor. The Vixen five inch Newtonian is $200 and change and I'll bet they've paid more attention to consistency than some of hte other lines. At f/5 and five inches it would give just under three degrees with a Pan Optic 24 ($300) and so for $500 you get a wide field instrument where both components can be resold later. But I haven't been through a dozen of the five inch Newts so alas I'm just guessing that Vixen would do better there than Orion or Harding.

I think there are some Mak Cass's out there that would be a better choice for the money.

regards
Greg N

regards greg n

On one hand the Orion has an FPL-53 element though still a doublet and on the other hand the Astro-Tech is a triplet but of unknown glass type.

It is my understanding that the Astro-Tech 111EDT uses FPL-51 as the ED element. I have had a chance to use one a bit and compare it to the AT-102ED. Being a 111mm triplet it is definitely heavier than AT-102ED but the improved color correction of the Triplet is quite apparent. On bright stars it seems quite clean in focus and even out of focus though I will have to do more in that regard. I have yet to do a side by side, but my guess is that the correction would be probably similar to my 80mm Megrez II FD.

I hope to get some more time to try it out.

Jon

There have been a few things said about the new wave of cheap triplets.
First is, a triplet does not mean APO or excellence in quality and manufacture.
Second is, not how many elements or what they are made of, but how well matched these elements are and how well made optically they are is the important information.
If you want a triplet, buy a reputable brand, so that you know what you are going to get. Otherwise it is a crap shoot.
I have a Meade 127ED APO doublet that is about as well corrected as a few so called APOs that I have seen. It is not a true APO as compared to an AP or another high end APO, but visually it is close. The funny thing is, that it is made from FPL-51, but its mating element must be right, because it is well corrected.
But, compared to my 80mm Lomo Triplet APO, it is not a contest when taking photos. This is when the blue bloat will show.
So,what do you want to do with the scope and what do you expect from it?

Len,

My recommendation is to not rush your decission. Take your time and do your homework. Post in a forum and see if there is anyone near you that has one of the scopes you're interested in and try to get some viewing time. This is the one way you are least likely to go wrong. Also, most owners that post here on AM are usually willing to trade emails and even talk on the phone to help. I've doen this a number of times and it sure helps.

Hope this helps.

R,

Joe

Hi.

The AT111 uses FPL51 and it is TMB designd.

I owen one for a month already and tested the scope on various targets - wide field,plenetary and double stars. I can say that this scope did not show any CA even on Sirus up to X300. views are very sharp and using the scope for planetary and especialy double star work is a pleasure.
Mechanicaly the scope is also graet . very solid foucuser that do not give mutch to the FT I have on my GENESIS SDF .

I have no relation nor any other interest to the company who makes it or sells it ....

Amit